This invention relates generally to an industrial waste water treatment cleaning method and apparatus. More particularly, the invention relates to the monitoring of conditions at the water contamination site and feeding information relating to the monitored conditions forward to a waste water treatment cleaning controller.
Waste water treatment facilities are used to reduce and/or eliminate contaminants in water used in industrial settings. For example, water which is used in industrial laundries is often contaminated with dirt, dyes, oils, greases, ink and other chemicals. Prior to discharging the water into the public sanitary sewer (or other discharge outlet), the water is treated. The treatment process generally includes an equalization tank for providing a more uniform output of water, a flow meter for monitoring the output from the equalization tank, and a series of pumps for injecting water treatment chemicals. A dissolved air flotation tank (xe2x80x9cDAFxe2x80x9d tank) is located downstream of the series of pumps. The DAF tank is the location where the chemical reactions occur (e.g., the reactions between the injected chemicals and the contaminants in the waste water), where air is injected into the water, and where skimming of solids occurs. More specifically with regard to the chemical reactions, such reactions are commonly known as flocculation and coagulation which are discussed briefly further below.
The drawbacks of such prior art systems generally stem from the non-uniformity of the concentrations and the unknown types of the contaminants in the water. However, even if the contaminants are known, because of the delays associated with the contaminants reaching the DAF tank from the various contamination points, it has been difficult to adjust the amount of injected chemicals to coincide with the actual contaminated water reaching the DAF tank.
Several types of systems have attempted to provide sensors to determine the types of contaminants which are contained in the waste water. However, these systems suffer in that the sensors are intrusive into the system and may become fouled by the waste water. Further, the physical nature of such systems require a time delay for the actual contaminants reaching the reaction tank.
In view of the above, there is a need for a method and apparatus for quantitatively identifying when a more severely contaminated volume of waste water will be discharged and for more accurately treating the waste water by elevating the amount of injected chemicals at the correct time (e.g., when such contaminated waste water reaches the reaction or DAF tank).
The present invention addresses the foregoing problems of the prior art industry by achieving more precise control of the injected chemicals with a feed-forward controller apparatus and method. The present invention achieves improved control by adjusting the chemical injection pumps in response to signals from the contaminant zone. This control is performed with any necessary delays to accommodate the time required for the contaminated water to reach the reaction or DAF tank. The present invention also continuously monitors flow rate information from a meter which is located downstream of the equalization tank and upstream of the chemical injection pumps. By using both the data from the contamination points and the flow meter, the chemical injection pumps more accurately provide the necessary amount of chemicals to accommodate both volume of contaminated water and contaminant concentrations in the waste water. By these and other improvements, actual injected chemical usage is optimized and the discharged water is more uniformly treated.
The invention provides both a method and apparatus for receiving the necessary input signals from both the contamination points and the flow meter(s). The received signals are processed and the delay from the associated contamination point is determined and a flag is set. When the necessary delay has occurred, the processor increases or boosts the injection rate of the treatment chemicals in accordance with the received signals. Such increases may be additive depending on the number and type of signals received from the contamination points. Additionally, if the flow meter is experiencing an increase flow rate, then the processor may boost the injection rate in response thereto.
One advantage of the present invention is that the concentration of the chemicals used to treat the waste water is delivered as the actual soils reach the reaction tank. This is accomplished without introducing sophisticated sensors into the waste water stream. Instead, the type of soils being introduced are monitored at the contamination points and a signal is transmitted to a controller. The controller determines the time and rate that chemicals should be introduced in order to optimize the concentrations in the reaction tank.
Therefore, according to one embodiment constructed in accordance with the principles of the present invention, there is provided an apparatus for controlling the injection of chemicals in a waste water treatment facility, comprising: means for monitoring one or more contamination sites and generating a contamination signal in response to the type of contamination; a flow meter for monitoring the volume of waste water discharged from the contamination site and for generating a flow volume signal; a metering device for portioning a chemical into the waste water, the metering device operating in response to a control signal; and a controller operatively connected to the monitoring means and the flow meter, the controller receiving the contamination signal and the flow volume signal and generating a control signal for the metering device in response, whereby the amount of chemical for treating the waste water is optimized.
According to another embodiment constructed in accordance with the principles of the present invention, there is provided a method of controlling the addition of chemicals to waste water from a waste water contamination site, the method comprising the steps of: monitoring one or more contamination sites and generating a contamination signal in response to the type of contamination; measuring the volume of waste water discharged from the contamination site and generating a flow volume signal; portioning a chemical into the waste water in response to a control signal; and integrating the contamination signal and the flow volume signal, and generating a control signal for portioning the chemical in response, whereby the amount of chemical for treating the waste water is optimized.
In further accordance with the principles of the present invention, there is provided an apparatus for controlling the introduction of chemicals into waste water from one or more laundry washer sites, comprising: a monitor device at the one or more laundry washer sites for generating a feed forward signal in response to the type of contamination; an equalization tank for collecting the waste water from the one or more laundry washer sites; a chemical treatment tank; a fluid communication means for directing the waste water from the equalization tank to the chemical treatment tank; a flow meter, installed in the second fluid communication means, for monitoring the volume of waste water discharged from the equalization tank and for generating a flow volume signal responsive thereto; a plurality of pumps for introducing waste water treatment, chemicals into the waste water in response to control signals, wherein the pumps introduce the chemicals in the second fluid communication means; and a controller operatively connected to the monitor device and the flow meter, the controller receiving the feed forward signal and the flow volume signal and generating a control signal for the pumps in response, whereby the amount of chemical for treating the waste water is optimized.
These and other advantages and features which characterize the present invention are pointed out with particularity in the claims annexed hereto and forming a further part hereof. However, for a better understanding of the invention and the advantages obtained by its use, reference should be made to the drawing which forms a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the present invention.